MAP4K4 Inhibition Promotes Survival of Human Stem Cell-Derived Cardiomyocytes and Reduces Infarct Size In Vivo.
Fiedler LR., Chapman K., Xie M., Maifoshie E., Jenkins M., Golforoush PA., Bellahcene M., Noseda M., Faust D., Jarvis A., Newton G., Paiva MA., Harada M., Stuckey DJ., Song W., Habib J., Narasimham P., Aqil R., Sanmugalingam D., Yan R., Pavanello L., Sano M., Wang SC., Sampson RD., Kanayaganam S., Taffet GE., Michael LH., Entman ML., Tan T-H., Harding SE., Low CMR., Tralau-Stewart C., Perrior T., Schneider MD.
Heart disease is a paramount cause of global death and disability. Although cardiomyocyte death plays a causal role and its suppression would be logical, no clinical counter-measures target the responsible intracellular pathways. Therapeutic progress has been hampered by lack of preclinical human validation. Mitogen-activated protein kinase kinase kinase kinase-4 (MAP4K4) is activated in failing human hearts and relevant rodent models. Using human induced-pluripotent-stem-cell-derived cardiomyocytes (hiPSC-CMs) and MAP4K4 gene silencing, we demonstrate that death induced by oxidative stress requires MAP4K4. Consequently, we devised a small-molecule inhibitor, DMX-5804, that rescues cell survival, mitochondrial function, and calcium cycling in hiPSC-CMs. As proof of principle that drug discovery in hiPSC-CMs may predict efficacy in vivo, DMX-5804 reduces ischemia-reperfusion injury in mice by more than 50%. We implicate MAP4K4 as a well-posed target toward suppressing human cardiac cell death and highlight the utility of hiPSC-CMs in drug discovery to enhance cardiomyocyte survival.